AND OF EXPOSED MUCOUS MEMBRANES. 653 
Black found in the saliva of ten healthy individuals the Staphy- 
lococeus pyogenes aureus seven times, Staphylococcus pyogenes al- 
bus four times, and Streptococcus pyogenes three times. On the 
other hand, Netter found Staphylococcus aureus only seven times in 
one hundred and twenty-seven individuals examined. Miller also 
has rarely found the pus cocci in the mouths of healthy persons. 
Streptococcus pyogenes was not found by Vignal in his extended 
researches. The experiments of the writer, of Vulpian, Frankel, 
Netter, Claxton, and others show that the micrococcus which in 
1885 I named Micrococcus Pasteuri, and which is identical with the 
‘ diplococcus pneumoniz ” of German authors, is frequently present 
in the healthy human mouth—now called Micrococcus pneumonize 
croupose. Netter examined the saliva of one hundred and sixty-five 
healthy individuals and obtained it in fifteen per cent of the number 
examined, 
Another pathogenic micrococcus which is frequently present in 
the mouths of healthy persons is the Micrococcus tetragenus of Koch. 
The following pathogenic bacteria have also been isolated and de- 
scribed : Bacillus crassus sputigenus (Kreibohm), Bacillus salivarius 
septicus (Biondi). The Streptococcus septo-pyzemicus of Biondi is 
described as having characters identical with those of the Strepto- 
coccus pyogenes of Rosenbach. Two other pathogenic species de- 
scribed by Biondi were each found in a single case only. Miller 
has described the following pathogenic species isolated and studied 
by him: Micrococcus gingives pyogenes, Bacterium gingive pyo- 
genes, Bacillus dentalis viridans, Bacillus pulpz pyogenes. 
Rosenthal (1893) examined the secretions from the mouths of 
fourteen individuals and obtained twenty-eight different bacteria; of 
these twenty-one had been previously described. Five species be- 
lieved to be new are described in detail by Rosenthal, viz.: Sarcina 
viridis flavescens, Micrococcus Reessii, Micrococcus ochraceus, Dip- 
lococcus Hauseri, Bacterium cerasinum. 
Vignal has tested a considerable number of microérganisms, 
obtained by him in his cultures from the healthy human mouth, with 
reference to their peptonizing action upon various kinds of food, with 
the idea that some of them may have an important physiological 
function of this kind. Out of nineteen species he found ten which, 
after a longer or shorter time, dissolved fibrin, nine which dissolved 
gluten, ten which dissolved casein, and five which dissolved albumin; 
nine changed lactose into lactic acid, seven inverted cane sugar, seven 
caused the fermentation of glucose, and seven coagulated milk. 
Sanarelli (1891) has shown that normal saliva has the power 
of destroying the vitality of a limited number of certain patho- 
genic bacteria, including the following species: Staphylococcus 
pyogenes aureus, Streptococcus pyogenes, Micrococcus tetragenus 
